E-Genting Programming Competition 2004

1. E-Genting Programming Competition 2004 Pre-Competition Workshop, Week 2 28 September 2004

2. Languages and Compilers • A high-level language defines a virtual machine. A programmer should be able to write in a high-level language without regard to the code that might be generated by the compiler of that language. • A high-level language is a kind of shorthand for the instructions that will be executed by the computer. A programmer should always be mindful of the machine-level consequences of a particular high-level construct.

3. SQL Statement Processing

4. B-Tree Structure

5. B-Tree Operations template <typename Key_t, typename Row_t> class BTree_c { public: void BtReset () { /*...*/ } // Position the row pointer at the beginning of // the tree bool BtFind (const Key_t *key) { /*...*/ } // Position the row pointer at the row with key // 'key', or if no such row exists, the row with // the next highest key. Return 1 if the key // was found, otherwise 0. bool BtRead (Row_t *row) { /*...*/ } // Read the row that the row pointer is pointing // to and load it into the location addressed by // 'row'. Move the row pointer to the next row // in the tree. Return 1 if a row was read. // Return 0 of the row pointer is pointing to the // end of the tree. };

6. Example Schema // Customer file create table custFile ( custId integer not null, // Customer identifier custName char(40) not null // Customer name ); create index custIdInd on custFile (custId); // Purchases file create table purFile ( purId integer not null, // Customer identifier purNo integer not null, // Purchase number purVal integer not null // Purchase value ); create index purIdNoInd on purFile (purId, purNo);

7. Query Translation

8. Optimisation